My bro is looking to buy a small sub.

What small subwoofer is recommended?
I have followed chess's thread on the Sony SA-WM40
which seems to be a great bargain, but it is too big for him.

I know sunfire does good small subs.
9 x 9 x 9 inches cabinet, although a bit pricey at $900

Anything else you would recommend?

Thanks

One of my friends just bought a small set of Infinity Subs for his HT. They are one of the best small subs I've ever heard.

If the size of the Sunfire line is your standard for small, that leaves few options. I thought the Sunfire subs sounded good when I heard them. They pack a lot of punch for their size. I know Paradigm makes a bookshelf 8 inch sub, but I have not heard it. Stores around me did not carry it. I do not know of any other subs that are really that small. Check out the paradigm if you can find it, or just get the smallest 8 inch sub you can find.

I think B&W has a new small sub (Sunfire sized), but it probably will fall on the pricey side, too.

Is it the floor space or the entire size (Wife Acceptance Factor) of the sub that he is concerned with? If it's just the size of the footprint, then I would recommend a sonotube type sub such as a Hsu Research or SVS - the Hsu has the smaller footprint of the two (under 1 sq.ft I think). They are about 3-4 feet tall. If his wife/girlfriend won't let him have a larger sub, then it doesn't get much smaller than the Sunfire.
If he doesn't have a wife/girlfriend but still doesn't want the larger sub, then I'd have to ask, "Are you sure that your brother is a guy?" ;)

Just about everybody out there sells small subwoofers now, following the design of Bob Carver (Sunfire). Monitor Audio, Pinnacle, B&W, REL, Velodyne, M&K, and a bunch more. There's also the taller sub of HSU and SVS that have a really small foot print (about a square foot) and supposedly sound better than anything out there for the price. There's also IN WALL subwoofer, NHT makes one and I think a few other's do as well, like Atlantic Tech. Any sub from one of those manufaturers would kick ass. If you just want a straight up suggestion here goes:

M&K K-9 Subwoofer: 8 incher, 75 watts (150 peak) measures 10x10x13 inches and costs only $550 retail. Odds are you can get it from Tatumelectronics or some other retailer for well under $500. In my opinion M&K probably makes some of the best HT subs out there, I'm sure this one doesn't fall far behind. Especially for that small of a room.

Good luck.

Thanks for all the suggestions, we'll check them out.

The reason he is looking for a small sub (footprint and size) is because he travels, and would like to bring it with him. :)

Now THAT I can DEFINITELY respect! :)